This invention relates to a stringed instrument, and particularly to reinforcing a structure preventing the neck of the stringed instrument from deforming.
A stringed instrument ordinarily has a body, a neck which is joined to the body and a head at the top of the neck, with at least one string and usually a plurality of strings stretched between a bridge on the body and a respective peg nut for each string which is typically on the head. The strings produce a tensile force between the peg nut and the bridge which causes upward deformation of the neck. A bent neck prevents production of correct musical intervals or it becomes difficult to reach the high positions toward the body end of each string, that is the end located close to the body. As the strength of the neck is low, a longer time will be required for the correct intervals to be obtained as the neck part is gradually deformed at the time of tuning.
To cope with the above discussed problem, it is known to place a truss rod having a bar-shaped iron core in the neck. This improves the strength of the neck by providing a repulsive force which counteracts forces tending to bend the neck.
Another known structure of a stringed instrument has a strong wooden material known as bubinga, which is held at the center of the neck. Alternatively, a metal plate having a convex shape is buried in the neck as a reinforcing material, as described in the Official Publication of Toku Kai 2001 13957.
In recent years, however, there has been an increasing demand for reduction of the size and particularly the thickness of the neck, particularly of guitars. This has made it increasingly difficult to place various reinforcing materials and structures, as described above, in the neck of the stringed instrument. Furthermore, the stringed instrument as a whole requires a simple reinforcing structure for the neck.
The invention has the object of overcoming the above described problems. A reinforcing structure for the neck of a stringed instrument, according to the invention, has an extremely simple structure which provides the neck with high strength and increased resistance to bending forces acting upon the neck.
In addition, the reinforcing structure for the neck of the invention allows bending of the neck to be adjusted and corrected.
In one embodiment of the invention, the reinforcing structure for the neck of a stringed instrument comprises a longitudinally extending, rigid, preferably plate, bar-shaped body extending along the longitudinal direction of the neck and disposed under a finger plate on the top side of the neck. The bar-shaped body has a cut groove which extends from the instrument body end of the bar shaped body toward the instrument head end of the bar shaped body. The plate bar-shaped body is divided into a head-side grooveless portion, a body-side groove upper portion and a body-side groove lower portion which are separated by the groove. The head-side grooveless portion and the body-side groove upper portion are bound securely along the entire length of the bar-shaped body to the underside of the top side of the neck, and, particularly to the underside of the finger board, and the body-side groove lower portion is detachably secured to the neck only at a location toward the instrument body end, i.e. the open groove end.
In another embodiment of the invention, the reinforcing structure for the neck of a stringed instrument has a plate bar-shaped body which is formed approximately in the form of U as viewed in a plane parallel to the top side of the neck and including a plate bar on the right side and a plate bar on the left side joined by a grooved body end connector. Therefore, the groove extends through the body end connector and into both of the right and left side bars from their instrument body ends toward their instrument head ends.
As a further feature of the invention, the terminal positions of cut grooves formed in the right-side plate bar and left-side plate bar may be the same distance into the bars from their body ends or may be different distances into the bodies from those ends because the different strings across the neck apply different upward bending forces on the neck.
A further feature of the invention relates to a reinforcing structure for the neck of a stringed instrument having tensile means that pulls the body-side lower part toward the body of the stringed instrument for generating thereby a force which counteracts tensile forces tending to deform the neck.